You can offer the featured listing and charge for them whereas the listing itself is free. The customer would have the option to check the "featured" option while listing the ad. The listing period however would be the same as the featured listing period (unless you manually uncheck the featured option).
If an item is sold the seller has the option to pause an ad, then it won't show up anymore. Or they can decide to mark it sold and leave the ad alive (as some kind of advertising).
If you check "prune ads" the ad would be unpublished after it has expired (not deleted though).
There is no limit for ads.
You are not forced to offer paypal and can turn it off.
You can allow up to 8 images (and with a small modification you could also allow more)
sexy-bookmarks is included but you can switch it off if you don't want it.
Post an item is a three step procedure. You could check out the theme demo
Demo Center | AppThemes
You are free to remove all unwanted fields and create fields that suit your needs. You can hide the "expired field" via CSS.
Hope this helps ..